The huge Rim Fire in and around California's Yosemite National Park hasn't yet caused problems at the Hetch Hetchy Reservoir that provides water to 2.6 million people in the Bay Area. There have been fears that falling ash will pollute the water there.
But now, the San Francisco Chronicle reports, "wildfire experts say problems for San Francisco's water agency may come later. Hetch Hetchy's pristine waters will be vulnerable to eroding hillsides as the fire leaves behind torched soil that can't absorb autumn rains and leveled forests that no longer anchor steep mountain slopes."
The fire grew to 187,466 acres as it burned into its 12th day. Containment inched up to 23 percent.
Several evacuation warnings were in place as of Wednesday morning and at least mandatory evacuation was ordered for residences north of Old Yosemite Road. For full details, visit our Fire Tracker page.
There's also word from KQED Wednesday morning that the flames are "perilously close to a longstanding experimental forest near Sonora. Losing it would be a setback for forestry and as fate would have it, fire management. For 80 years, the Stanislaus-Tuolumne Experimental Forest has been a trove of data for foresters."
View Rim Fire in a larger map | Last updated 8/26/13